Screw



FIG. 1 is a left side perspective view of a screw;

FIG. 2 is a right side perspective view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a right side elevational view thereof; and,

FIG. 5 is a left side elevational view thereof.

The broken lines rendered in FIGS. 1 and 2 illustrate portions of the screw and form no part of the claimed design. 

CLAIM The ornamental design for a screw, as shown and described. 